EDM songs are usually referred to as tracks primarily because they are not songs as in other genres of music. Instead, EDM pieces tend to be composed of a range of different tracks that are put together into a mix. A song usually implies that there is a beginning of a story, a middle, and an end.
However, EDM tracks usually do not tell a story like traditional songs do. Instead, most of them are geared towards triggering a specific feeling through sampled sounds rather than words. This could the main reason why EDM pieces are referred to as tracks and not as songs.
